Australian Antarctic Division: Leading Australia’s Antarctic Program

VHF radar observations

Winds through the troposphere and lower stratosphere

The image below shows the results of observations over a day. Coloured arrows that indicate horizontal wind direction are plotted against height or altitude in kilometres and time. An upward pointing arrow indicates wind blowing toward the north, one pointing to the right indicates a wind blowing toward the east (as on a compass dial). The colour of the arrow indicates the wind speed as shown in the scale bar on the right hand side, ranging from dark blue for low velocity to yellow for high velocity. Typically winds are measured between 0.5 and 10–15 km. The lack of an arrow indicates that no data was obtained for that height and time. The base height of observations is defined by the parameters under which the radar is operating.

Horizontal wind speed and direction recorded by the VHF radar at Davis.

Meteor detections

The image below is a map of the directions in which meteors trails have been detected. For each dot (detection) the distance from the centre gives the angle from the zenith (overhead). North is upwards and East is to the right. Most meteors are detected in the height range 80–95 km. The lack of detections to the North-East and the South-West is due to the relative insensitivity of the meteor receiver antennas in those directions. Note that the radar reflection maximises at 90 degrees to the meteor trail. The total number of detections during the period of observations is indicated at the top of the image.

The angle of arrival for meteor trail reflections recorded by the VHF radar at Davis.